ABSTRACT
BACKGROUND: Diet quality has been inversely associated with overall mortality in white populations, but the evidence in African-American populations is limited. OBJECTIVE: The goal of the present study was to assess diet quality in relation to all-cause mortality in the Black Women's Health Study, a follow-up study of African-American women begun in 1995. METHODS: Data used in this study were obtained via biennial questionnaires from 1995 to 2011. Based on food-frequency questionnaire data collected in 1995 and 2001, we calculated an index-based diet quality score [Dietary Approaches to Stop Hypertension (DASH)] and derived dietary patterns (prudent and Western) with the use of factor analysis. We followed 37,001 women who were aged 30-69 y and free of cancer, cardiovascular disease, and diabetes at baseline for mortality through 2011. Multivariable Cox regression was used to estimate HRs and 95% CIs. Analyses were conducted in 2014. RESULTS: Based on a total of 1678 deaths during 16 y of follow-up, higher DASH scores were associated with reduced all-cause mortality (HR: 0.75; 95% CI: 0.63, 0.89 for highest vs. lowest quintiles). The DASH components most strongly associated with lower mortality were high intake of whole grains and low intake of red and processed meat. A Western dietary pattern, characterized by high intake of red and processed meat, was associated with increased all-cause mortality rates (HR: 1.37; 95% CI: 1.17, 1.60 for highest vs. lowest quintiles of score); a prudent dietary pattern was not associated with risk. CONCLUSION: A DASH-style diet high in intake of whole grains and low in consumption of red meat is associated with reduced mortality rates in healthy African-American women.
Subject(s)
Black or African American , Diet , Feeding Behavior , Mortality/ethnology , Adult , Aged , Body Mass Index , Cardiovascular Diseases/epidemiology , Cohort Studies , Diabetes Mellitus/epidemiology , Diet, Western , Endpoint Determination , Factor Analysis, Statistical , Female , Follow-Up Studies , Humans , Middle Aged , Multivariate Analysis , Neoplasms/epidemiology , Nutrition Assessment , Patient Compliance , Proportional Hazards Models , Risk Factors , Surveys and Questionnaires , Women's HealthABSTRACT
BACKGROUND: Physical activity has been associated with reduced risk of breast cancer. Evidence on the association in African Americans is limited. METHODS: With prospective data from the Black Women's Health Study, we assessed vigorous exercise and walking in relation to incidence of invasive breast cancer overall (n = 1,364), estrogen receptor-positive (ER(+), n = 688) cancer, and estrogen receptor-negative (ER(-), n = 405) cancer, based on 307,672 person-years of follow-up of 44,708 African-American women ages 30 years or older at enrollment. Cox proportional hazards models estimated incidence rate ratios (IRR) and 95% confidence intervals (CI). RESULTS: Vigorous exercise at baseline was inversely associated with overall breast cancer incidence (Ptrend = 0.05): the IRR for ≥7 h/wk relative to <1 h/wk was 0.74 (95% CI, 0.57-0.96). The association did not differ by ER status. Brisk walking for ≥7 h/wk was associated with a reduction similar to that for vigorous exercise. Vigorous exercise at the age of 30 years, 21 years, or in high school was not associated with breast cancer incidence. Sitting for long periods at work or watching TV was not significantly associated with breast cancer incidence. CONCLUSION: High levels of vigorous exercise or brisk walking may be associated with a reduction in incidence of breast cancer in African-American women. IMPACT: These results provide informative data on a potential modifiable risk factor, exercise, for breast cancer in African-American women.
